Adds a contact to a client account. Request Parameters Parameter Type Description Required action string “AddContact” Required clientid int Required firstname string Optional lastname string Optional companyname string Optional email string Email address to identify the contact. This should be unique if the contact will be a sub-account Optional address1 string Optional address2 string Optional city string Optional state string Optional postcode string Optional country string 2 character ISO country code Optional phonenumber string Optional tax_id string Optional email_preferences[general] boo